Time delay relay circuit



Feb. 5, 1946. R. nl GIUSEPPE TIME DELAY RELAY CIRCUIT Filed Oct. 4. 1940FIGQZ lluf f m3 @Mii m4 Patented Feb. s, 194s TIME DELAY RELAY CIRCUITRenato DI Giuseppe, Rome, Italy; vested in the Alien Property CustodianApplication October 4, 1940, Serial No. 359,791 In Italy November 11,1939 1 claim.

` made of the condenser, but the circuit is so arranged that the relayoperating the switch or contact breaker to he controlled, operatesduring the charging of the condenser until the charging current,supplied from a constant voltage source, falls below a certainpredetermined value; the system of time-delay control so obtained beingused in conjunction with means adapted to repeat periodically theoperation at predetermined intervals of time, always equal to eachother.

The invention comprises essentially an electric circuit in which isinsertedv a switch comprising pairs of two or more contacts controllinga relay of normal type, a condenser traversed by a current of suiiicientintensity for maintaining attracted the armature of said relay during apredetermined time, said relay being connected by a key adapted to openone pair of contacts for starting the charge oi the condenser, andadapted to close the other pair of contacts which re-establishes thecircuit in place of the key.

The interval ci' time during which the circuits maintain the relayclosed constitutes the measured unit of time.

. The device according to the present invention is shown schematicallyin various embodiments and by Way of example in the attached drawing, inwhich:

Fig. l shows a circuit in which a relay is attracted immediately uponapplication of voltage to its winding and remains attracted for a giventime after the operating switch has been opened. (Time-delay dropoutrelay.)

Fig.` 2 shows a circuit similar to that'shown in Fig. l, arranged so asto compensate any variations of voltage of the supply current.

Fig. 3 shows a circuit similar to that shown in Fig. 2, comprising atime-delay relay which is energized into actuated position after adetermined time from its connection, said actuated condition ceasingimmediately upon its disconnection. (Time-delay pickup relay.)

Fig. 4 shows a circuit similar to those illustrated in Figs. 2 and 3,but provided with a timedelay relay retarding its action both on itsconnection and disconnection. (Time-delay pickup and dropout relay.)

The timed circuits which I describe may be arranged to actuate anyconventional electrical impulse actuatable instrument as a counting o rrecording system.

Fig. 1 Shows schematically a circuit so arranged between supply mainsthat the relay armature provided is attracted immediately upon itsconnection, and continues to be attracted for a determined time afterthe voltage supply has been disconnected. (Time-delay dropout relay.) Insuch circuit, the relay winding I, is energized immediately on closingbutton Il, while condenser I8 is short circuited by said contact buttonil, and is thereupon discharged. When the circuit is opened, through theopening of contact hutton I'l, the relay winding I continues to be traversed by current, until the value of said charging condenser currentfalls below a certain determined value.

Fig. 2 shows schematically a circuit similar to that shown in Fig. 1,and connected across supply mains, but provided with means adapted tocompensate any variations of voltage of the sup ply current. These meansconsist in forming the relay on an E shaped core, comprising two windings I4 and I5 on the respective outer legs, and an oscillating bararmature I6 pivoted between said core windings on the legs, one of whichmay be connected as the relay winding I shown in Fig. 1, and the othermay be shunted across the supply voltage with an adjustable resistancecon nected in series, thus acting as an opposing force.

With the arrangement just described, both the actuating force of therelay, due to the charging current of condenser I8, and the opposingforce which causes the relay contact and the condenser to bedisconnected, when said actuating force de-s creases, are proportionalto the voltage of the cur-n rent, i. e., they vary similarly with thevariations of the latter, and consequently the operation of the devicedepends solely on the electric charu acteristics of the circuit, and soremains practically constant even during any variations of the voltage.

In the circuit shown in Fig. 2, the rheostats I9 and 20 are used foradjusting, within certain limits, the time characteristic of thecircuit.

Fig. 3 shows a circuit similar to that shown in Fig. 2, with whichhowever the opposite eect is obtained, i. e., a retardation of theclosing of the relay (time-delay pickup relay). In this circuit,winding- Il is the active one, while winding I provides the opposingforce; these two windings are so designed that on pressing the key 2|from its normal spring urged position as shown, the winding Il isconnected and. the normally closed short circuit across condenser I8 isopened and condenser I2 starts to charge through winding I5 energizingthe latter, but the force produced by winding I4 is not sufficient forattracting immediately the movable armature IS, and consequently a timet has to pass between said connection and the actual attraction ofarmature I6, after which the current charge of condenser I8, drops tosuch a low value, that the current traversing the winding i5 falls belowand is overcome by that traversing the winding I4. Also in this case thetime-delay depends on the values of condenser I8 and resistances I9 and20.

The relay shown in Fig. 3 has a quick return to unactuated position,viz.; as soon as key 2| is released, the movable pivoted armature I6 isimmediately attracted again by the winding I5.

The circuit shown in Fig. 4 is a time-delay pickup and time delaydropout relay. In fact, in this circuit, on pressing the button 2l, theoperation above described for the circuit of Fig. 3 is obtained, and onreleasing said key 2l, the operation described for the circuit of Fig. 2is obtained. The values of the two time-delays depend on the values ofthe condensers I8 and 23 and of the resistances I9, 20 and 22. CondenserI8 is connected across the xed contacts of switch 2l which makeconnection to the restraining winding I5, and by its charging currentcauses winding I5 to restrain the actuation of relay armature I 6 whenbutton 2l is depressed. Condenser 23 is connected across the fixedcontacts oi' switch 2| which make connection to the actuating windingI4, and by its charging current delays the reduction of the currentthrough actuating winding Il to armature releasing value when button 2|is released from depressed position.

It will be understood that the controlling circuit of an electricallyactuatable instrument whose operation is to be controlled with timedelay characteristics, may be connected to the controlled contact ofarmature Ii.

What I claim is:

In control means for an electric timing circuit, electromagnetic relaymeans having a set of controlled contacts and further having anoperating and a restraining winding magnetically opposing each other, aswitch having two positions and having a rst pair and a second pair oi'controlled contacts and adapted in a given position to selectivelyconnect together either said first pair or said second pair of contactsbut not both pairs, a source of electrical energy, a iirst contact ofeach of said pairs being connected to a first terminal of said source,the second contact of said first pair being connected to a rst terminalof said operating winding and the second contact of said second pairbeing connected to a first terminal of said restraining winding, thesecond terminals of said windings being connected to the second terminalof said source, and a pair of electrical time delay circuits eachcomprising electrical energy storing means respectively connected acrosssaid'pairs of contacts respectively.

RENATO DI GIUSEPPE.

